HIV Testing and Screening

HIV stands for Human Immunodeficiency Virus which attacks the human immune system. If left untreated, the immune system will eventually collapse. AIDS (Acquired Immune Deficiency Syndrome), a series of symptoms and illnesses, occurs during the final stage of HIV infection.

The earlier HIV is diagnosed, the earlier one can seek necessary treatment. Treatment helps HIV infected patients to enhance their normal and healthy life.

What is HIV Testing?

HIV Testing is the use of oral saliva or blood samples to detect the presence of HIV infection in the person through the detection of HIV antigens, HIV antibodies or HIV viral DNA/RNA.

Amongst various clinics that offer HIV tests in Singapore, Nuffield Medical Siglap is recognised as an approved rapid HIV testing clinic. We offer the latest HIV tests to provide accurate results based on the exposure.

Types of HIV Tests

Less than 3 days or 72 hours

Recommended HIV Test
No testing is available at this stage. You may wish to consider HIV PEP (Post Exposure Prophylaxis) if you have had a high risk exposure, i.e. unprotected sex with a commercial sex worker or high risk contact, or needlestick injury from a IV drug abuser.

Remarks
HIV PEP was shown to be >80% effective in reducing risk of HIV infection. In animal studies, it was shown that the earlier (<24 hrs) PEP is started, the more effective it is, with prevention rates reaching almost 100%.

10 - 14 days

Recommended HIV Test
HIV RNA/DNA Polymerase Chain Reaction (PCR) Test
1 – 2 weeks

Price
$600

Remarks
The HIV Viral PCR test looks for the presence of the actual HIV virus which will indicate positive infection by HIV.

28 days (4 weeks)

Recommended HIV Test
HIV P24 Antigen/Antibody Test

Turnaround time
1 – 3 days

Price
$120

Remarks
Recommended by UK Guidelines in HIV Testing 2008 – conclusive at 28 days post exposure.

Rapid HIV P24 Antigen/Antibody Combo Test (4th generation)

Turnaround time
20 min

Price
$150

Remarks
Fingerprick blood test.

Which test is most suitable for me?

Despite many different HIV test to choose from, you can decide on one by considering these 2 factors:

1. Accuracy

The accuracy of each tests depend on the window period. The window period is the time between your exposure to the infection, and the time when HIV infection can be detected.

Most HIV tests offer more than 99% accuracy, provided that the respective window period for each test is achieved. For example, the accuracy of HIV P24 Antigen/Antibody Test is more than 99% if there is at least 4 weeks of window period.

2. Turnaround time

Time taken for the results of HIV tests vary depending on the type of HIV test performed. It can be as fast as 20 minutes (HIV rapid tests), or 3 working days (HIV ELISA antibody tests) or even up to 2 weeks (HIV viral DNA/RNA).

You can choose the most suitable test depending on the time of exposure, and your urgency to obtain the results.

Time from HIV Exposure

Less than 3 days or 72 hours

No testing is available at this stage.

You may wish to consider starting HIV PEP (Post Exposure Prophylaxis) treatment if you have had a high risk exposure, i.e. unprotected sex with a commercial sex worker or high risk contact, or needlestick injury from a IV drug abuser within the last 72 hours. HIV PEP has been shown to be very effective (>80%) in reducing risk of HIV infection when started within 72 hours.

10 – 14 days

You may consider the HIV RNA/DNA Polymerase Chain Reaction (PCR) Test if your exposure is more than 11 days ago.

This test uses technology to amplify viral load from the blood, and it can detect small amounts of virus in a newly infected person. After infection, viral load is usually very high within the first 4 weeks and so this test can be used to confirm an early infection.

Indications for testing: To determine the HIV infection status in

Individuals whose HIV screening test by ELISA is reactive, but whose status is indeterminate or inconclusive by Western blot
High-risk individuals with a negative serological screen and a history of recent exposure
You will need to make an appointment in advance for this test. Results will take 7 – 10 working days.

14 – 28 days (2 – 4 weeks)

You may consider the

  • HIV Combination P24 Antigen/Antibody Test, or
  • the 4th generation HIV P24 Antigen/Antibody Combo Rapid test,

if your exposure is more than 16 days ago.

The HIV P24 antigen/antibody test is recommended by UK Guidelines in HIV Testing 2008 – conclusive at 28 days post exposure.

You may also consider screening for other STDs/STIs.

More than 28 days (> 4 weeks)

If your exposure is more than 28 days or 1 month ago, you can opt for the standard HIV Antibody Test.

You may also consider screening for other STDs/STIs.

Besides HIV, there are other diseases/infections that can be sexually transmitted. Learn more about our STD Testing and Screening and relative STD Treatments.